University of St. Andrews (UK)
University of St. Andrews: Mayan Mathematics
After a historical introduction, this site from the University of St. Andrews provides information about the mathematics of the Maya Civilization and shows just how advanced they were.
Foundation for the Advancement of Mesoamerican Studies
Famsi: Major Archaeological Sites: Tikal
Short history of the Tikal site. Check under the Research link for a Teacher Guide that could be used to study Mayan math and writing. Note that this site can also be viewed in Spanish.